Lacebark elm tree named ‘MON1’

ABSTRACT

A new cultivar of  Ulmus parvifolia , ‘MON1’, characterized by its uniform upright plant habit developing to an oval form at maturity and its hardiness at least to U.S.D.A. Zone 4b.

Botanical classification: Ulmus parvifolia.

Variety denomination: ‘MON1’.

BACKGROUND OF THE INVENTION

The present invention relates to a new and distinct cultivar of Ulmusparvifolia, and will be referred to hereafter by its cultivar name,‘MON1’. ‘MON1’ is a new cultivar of lacebark elm or Chinese elm, adeciduous tree grown for use as a landscape plant.

The new Ulmus was discovered as a single unique naturally occurringwhole plant mutation of Ulmus parvifolia as a 2-inch B & B tree in theInventor's nursery in fall of 1992 in Spring Grove, Ill.

Asexual reproduction of the new cultivar was first accomplished by theInventor by softwood cuttings in the summer of 1996 in Spring Grove,Ill. The characteristics of this cultivar have been determined to bestable and are reproduced true to type in successive generations.

SUMMARY OF THE INVENTION

The following traits have been repeatedly observed and represent thecharacteristics of the new cultivar as observed for 16 years in SpringGrove, Ill. These attributes in combination distinguish ‘MON1’ as aunique cultivar of Ulmus parvifolia.

-   -   1. ‘MON1’ exhibits a uniform upright growth habit developing an        oval shape on maturity.    -   2. ‘MON1’ exhibits cold hardiness at least to U.S.D.A. Zone 4b.

In comparison to the parent plant, Ulmus parvifolia, ‘MON1’ has anupright habit, whereas Ulmus parvifolia has an open and variable planthabit. ‘MON1’ can also be most closely compared to Ulmus parvifoliacultivars ‘Zettler’ (U.S. Plant Pat. No. 10,846) and ‘Whit XXX’ (U.S.Plant Pat. No. 16,883). Both cultivars are similar in developing uprightand oval plant habits, however ‘MON1’ differs in showing better winterhardiness as both cultivars are cold hardy to U.S.D.A Zone 5.

BRIEF DESCRIPTION OF THE DRAWING

The accompanying colored photographs of ‘MON1’ illustrate the overallappearance and distinct characteristics of the new Ulmus parvifolia. Thephotographs were taken of a plant sixteen years in age as grown outdoorsin Spring Grove, Ill.

FIG. 1 illustrates the overall plant habit in summer.

FIG. 2 provides a view of ‘MON1’ in winter and shows the overall plantstructure without foliage.

The colors in the photographs may differ slightly from the color valuescited in the detailed botanical description, which accurately describethe colors of the new Ulmus parvifolia.

DETAILED BOTANICAL DESCRIPTION

The following is a description of the new cultivar as grown outdoors andobserved for sixteen years in Spring Grove, Ill. The detailed botanicaldata was collected on a three year-old plant of ‘MON1’ that was grown ina 10-gallon container in New Hope, Minn. The phenotype of the newcultivar may vary with variations in environmental, climatic, andcultural conditions, as it has not been tested under all possibleenvironmental conditions. The color determination is in accordance withThe 2007 R.H.S. Colour Chart of The Royal Horticultural Society, London,England, except where general color terms of ordinary dictionarysignificance are used.

-   General description:    -   -   Botanical classification.—‘MON1’ is a cultivar of Ulmus            parvifolia.        -   Parentage.—Naturally occurring seedling selection of Ulmus            parvifolia.        -   Plant habit.—Deciduous tree with a uniform, upright and oval            habit.        -   Height and spread.—Reaches about 2.5 m feet in height and 5            feet in width (three year-old plant), reaches about 10.5 m            (35 ft) in height and about 4.5 m in width (15 ft) in            sixteen years.        -   Cold hardiness.—At least in U.S.D.A. Zones 4 to 9.        -   Diseases and pests.—No apparent disease problems have been            observed to date.        -   Root description.—Fibrous, freely branched.-   Growth and propagation:    -   -   Propagation.—Softwood cuttings and T-bud grafting.        -   Time required for graft development.—About 4 weeks to            develop in a 36-cell tree pot.        -   Growth rate.—Moderate.-   Stem description:    -   -   Shape.—Round to slightly oval.        -   Stem color.—Main trunk and secondary branches (bark) blend            of 97A and 97C, with lenticels 164A in color about 6 per 2            square centimeters, new growth; a blend of 199B and 199C.        -   Branching.—Irregular but primarily alternate, internode            length for secondary branches is an average of 2.5 cm.        -   Stem size.—Main trunk; about 1 cm in diameter (15 cm from            base) and 2.5 m in length, secondary branches; an average of            5 mm in diameter and 1 m in length, and tertiary branches;            an average of 3 mm in diameter and 50 cm in length.        -   Stem surface.—New growth is smooth with areas of pubescence,            mature bark has vertical striations and is somewhat            glaucous.-   Foliage description:    -   -   Leaf shape.—Elliptic to obovate.        -   Leaf division.—Simple.        -   Leaf aspect.—Held nearly horizontally to slightly pendant            stem.        -   Leaf base.—Oblique.        -   Leaf apex.—Broadly acute.        -   Leaf fragrance.—None.        -   Leaf venation.—Pinnate, 137C in color on upper surface, 138C            on lower surface with 145C midrib.        -   Leaf margins.—Serrated.        -   Leaf arrangement.—Alternate with terminal leaves on branch            larger.        -   Leaf internode length.—An average of 5 mm.        -   Leaf attachment.—Petiolate.        -   Leaf surface.—Glabrous on upper surface and finely            puberulent on lower surface.        -   Leaf size.—Mature to about 4.6 cm in length and 2.3 cm in            width.        -   Leaf color.—Mature growth; Upper surface; 137B, lower            surface; a color between 147B and 147C, new growth; upper            and lower surface 146B.        -   Petioles.—An average of 3 mm in length and 1 mm in width,            color is 146B, surface is pubescent.-   Flower description:    -   -   Flowers.—Typical for the species, characterized as            inconspicuous and occurring in early fall in Illinois.        -   Seed.—Seed production has not been observed, fruit            production is generally sparse for the species.

It is claimed:
 1. A new and distinct cultivar of lacebark elm tree named‘MON1’ as herein illustrated and described.